Looking to buy one of these two. Was dead set on the Marshall until I played the Fender for a few minutes. I was pressed for time, so I didn't get to really play the Fender much. It seemed the 30w Fender put out as much sound as the 50w Marshall. Any opinions from those who've played both?

I played both of them several times a while back when I was in need of a an acoustic amp. I thought the Marshall sounded significantly better and bought it. I don't remember which was louder. That was not important to me. I own neither now because I needed to move up to a larger system (PA). I would suggest playing both as you have, only for longer, and letting your ears decide. Hope this helps.

FWIW I have the Marshall AS50D which was purchased about a year and a half ago and am still very happy with it. I compared it against the Fender and Roland AC 60. Spent an hour in the Acoustic room of a guitar center with them. For my taste I liked the Marshall best. I liked the full sound and effects. I also liked the aesthetics. I ranked the AC60 second and the Acoustisonic third.

I have played through both and bought the Marshall. I play a few nursing homes with it each month (10) and it has not had a problem in over 2 years. In addition to sounding good it weighs in at around 23 lbs. which is important when you're lugging stuff around.

I tried the marshall, fender, and several others a few years ago. I ended up with the Marshall 50. It just seemed to sound the best for the price. The only drawback is that there isn't much of an EQ (but I use an EQ pedal, so no real biggie for me), but the notch filter comes in handy.

I wrung out the Marshall and the Acoustasonic when I bought my Taylor T5 - I'd been playing a Gibson 335 through a Peavey Bandit, but the Peavey just killed the Taylor. The Fender was the first one I tried, and it was enough to tempt me to throw the Bandit to the wolves; the sound was definitely better through the acoustic amp, but I felt the T5 had more potential for a smooth, silky ballad than the Fender could process.
Then I tried out a Marshall AS50D - it seemed to be able to produce anything the Fender could, with at least as much power. But the Marshall has a mellow side, when you want it, that I was not able to even approach with the Fender. I liked the controls and other features; it seemed to have everything I needed, and not a lot of stuff I'd never use. The Taylor T5 has a wide range of capability, and I felt the Marshall lets me use the guitar to it's full potential. After a couple years of playing it now, I'm still completely satisfied.
In fact, I like to leave it hooked up at home, and began searching Ebay ... I now have an AS100 as well, which I like even better!
To be fair, though, if I was playing an acoustic/electric guitar instead of the T5, I might choose the crisper tonal nature of the Fender.